Optical fiber network planning refers to a broad spectrum of activities including determining where, when and how much new optical network capacity, i.e., carrier facilities, must be established or added to the network in order to meet a demand for services through the network. More particularly, network service providers must perform technology selection, equipment sizing, traffic grooming and routing, cost analysis, and other related operations.
The United States telecommunications industry currently relies largely on a synchronous optical networking technology known as a Synchronous Optical Network (“SONET”). SONET is referred to as synchronous technology because the exact rates that are used to transport data are tightly synchronized across the entire network by atomic clocks. This allows for a significant reduction in the amount of buffering required between each element of the network when compared to asynchronous optical fiber technologies. In addition, unlike asynchronous technologies that only connect two points in a direct link, SONET allows several points to be connected in multiple types of architectures, e.g., a ring, mesh or grid, etc. These architectures are desirable because they are “self-healing” in the event that a fiber optic cable is cut.
A second developing synchronous optical networking technology that also uses the above “self-healing” architectures is called Dense Wavelength Division Multiplexing (“DWDM”). In DWDM, multiple colors of light are passed through a single fiber optic strand thus permitting multiple signals through that fiber strand. This increases the capacity of each fiber optic strand as compared to prior network technologies such as SONET. DWDM networks also allow individual wavelengths of light to carry different types of data traffic, such as for example, SONET traffic, Ethernet traffic, Fibre Channel, etc. DWDM wavelengths can also carry traffic at different rates, such as for example, OC-48 (2.5 Gbps), OC-192 (10 Gbps), etc. DWDM networks need not be terminated (i.e., converted from optical signals to electrical signals and then back again) at intermediate optical network nodes as is required by prior technologies such as SONET.
Various methods have been developed for determining the topology or structure of a SONET and/or DWDM optical fiber network. For example, one method is disclosed in commonly-owned U.S. Pat. No. 6,798,752, which is entitled Method and System for Determining Network Topology and is incorporated by reference herein in its entirety.
Given the many benefits and increasing demand for DWDM network technologies, it would be desirable to provide additional methods for determining DWDM network topologies and more particularly, to provide methods and systems for optimizing the structure of such systems based on the traffic expected or intended to be supported by such systems.